Mandrel-bar-supporting apparatus for piercing mills



INVENTOR ram W mm. muw mu & N

4 Sheets-Sheei 9M AW N R. c. STIEFEL MANDREL BAR SUPPORTING API ARATUS FOR PIERCING MILLS.

' Filed April 5; 1928 May 13, 1930 Jwrmzss- May 13,- 1930.

WITNESS R. c STIEFEL 1,758,413

MANDREL BAR SUPPORTING APPARATUS FOR PIERCING MILLS I I Filed April 5, 1928 4 Sheets She et 3 uvsmga May 13, 1930. R. c. STIEFEL 1,753,413

MANDREL BAR SUPPORTING APPARATUS FOR PIERCING MILLS Filed April 5, 1928 (sheets-sheep 4 INVENTOR HRH HHFIHH H HHH. H. L

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wrmess Maw Patented May 13,1930

UNITED STATES PATENT OFFICE RALPH c. srIEFEL, or ELLwoon CITY, PENNSYLVANIA Application filed April 5,

1 progressively envelops -the mandrel bar,

which must accordingly be somewhat longer than the pierced billet or tube at the end'of theoperatiom In some cases it is necessary to use mandrel bars of such lengths and diameters that if unsupported intermediate of their ends they buckle or otherwise fail to maintain the mandrels, in their proper positions. This is particularly the case when seamless tubing is produced directly by the piercing of billets without further working of the metal except that incident to finish-' ing operations.

An object of this invention is to provide simple and effective means for so supporting long mandrel rods that they will not buckle or otherwise fail to properly maintain mandrels in operative positions in'piercing mills and a further object is to provide mandrel barsupporting apparatus which also serves to guide the pierced portions of tubes or billets .during piercing operations, and thereby eliminate the necessity of providing special guides such as now used.

7 The invention is illustrated in the accompanying drawings of which Fig. 1 is a somewhat diagrammatic view of a piercing mill and mandrel bar supporting and billet-guiding apparatus associated with it, such apparatus beingpositioned for supporting a mandrel bar; Fig. 2 a' view similar to Fig. 1 showing the apparatus positioned fdr guiding the pierced portion of a billet; Figs. 3 and 4 enlarged plan views of a unit of the apparatus showing it in alternate positions; Figs. 5 and 6 sectional views taken on the lines VV and VIVI, of Figs. 3 and 4, respectively; Figs. '7 and 8 plan views of a unitof a modification of construction of the apparatus showing the unit in alternate positions; and Figs.'9 and 10 imnnnnn-nan-surronrme nrrnnn'rus. non LIPIERCJING: mLLs elevations of the units of Figs. 8 and 9 in the respectivealternatepositions there shown.

According to this inventionthere are provided intermediate the ends of a mandrel bar means for supporting it against lateralv as well as vertical deflections or movements, the

means being effective for this purpose until the forward pierced-end of a blank reaches the point of support of the bar. For long mandrel bars there are preferably provided a plurality of supports arranged at spaced intervals intermediate the ends of the bars, each support being independently operable to release the bar as or when the forward end of a blank reaches it. While the customary or any desired instrumentalities may be used for guiding pierced portions of billets, it is preferred to so construct the mandrel bar supports that when each is moved from its bar-supporting position it then becomes a guide for a pierced billet or tube.

Having reference now to the illustrative embodiments of the invention, there is shown in Fig. 1 a piercing mill comprising a pair of barrel-shaped piercing rolls 1 having their axes of,rotati0n disposed obliquely with relation to each other, and forming between them a piercing pass in which there is a mandrel2 attached to the end of a mandrel bar 3. The

ends of bar 3, the rear'end of which is suitably supportedby a holder diagrammatically guides preferably comprise pairs of blocks shown at 7. The combined supports and;

10 and 11, 10? and 11 and 10 and 11*? of like I constructions, thenumber of pairs of blocks used depending upon the conditions'of service.

scale in Figs. 3 and 5, the blocks are pivotally mounted on vertical pins 12 and 13 attachedat their lower ends to frame 6, the blocks be- Having reference to the support formed by blocks 10 and 11, illustrated to enlarged.

block being connected to the table by a dowel pin 18. For causing simultaneous movements of tables15 and 17, they are provided on their adjacent faces with intermeshing teeth 19 and 20, and for effecting their movements the outer face of table 15 is provided with a segmental pinion 21 which meshes with a-raek 22-suitably mounted for longitudinal movements. Oneendof-rack 22 is attached to a piston rod 23 having attached to it a pisten 24 arrangedin a pressure fluid cylinder 25 provided at its ends with pipes 26 and 27 foradmitting and exhausting pressure fluid.

'Thus by admitting pressure fluid to one end of-cylinder 25 and exhausting it from the other,-tables 15 and 17 and blocks 10 and 11 ,attachedto them-may be rotated upon their verticalga'xes. It-wi'll be understood, howeve,r;. ;-t;hatin place of the particular mechanisnrshown anddescribed various forms of prime movers and block connections may be used. I

On faces disposed preferably at right angles to each other, blocks 10 and 11 are provided with cooperating pairs of grooves to receive and support a mandrel bar and to guide the pierced portion of a blank. For supporting a mandrel, blocks 10 and 11 are provided with grooves 30 and 31, respectively, and for guiding the'piereed portion of a. blank these blocks are provided with grooves 32 and 33, respectively. In the positions that the blocks are shown in Figs. 3 and 5, their grooves 30 and 31 are in cooperative relationship for supporting a mandrel. bar, and

- in their positions shown in Figs. 4 and 6, their duct 35.

grooves 32 and 33 are brought into cooperative relationship for guiding the pierced portionof a blank; To suitably lubricate a mandrel bar engaged by blocks 10 and 11, block 10 may be provided on its top with a greasereceiving pocket 34, the lower end of which communicates with groove 30 through a In operation, the several pairs of blo cks 1O .and'11,'10"and 11, etc., are first sopositioned that their grooves 30 and 31 surround and adequately support mandrel bar 3 against both lateral and vertical deflections, the several pairs of blocks being shown in Fig. 1 as 'sopositioned. When the forward end of the pierced portion 5 reaches the first pair of mandrel bar supportingblocks 10 and 11, these blocks are caused to rotate through an angle of 90 in the direction of longitudinal movement of the blankto cause their supporting grooves 30 and 31 to disengage-the bar and to also cause their grooves 32 and 33 to come to billet-guiding positions. This procedure is repeated for each of the several pairs of blocks as the'forwardend of a blank reaches them. For thus controlling movements of the blocks, fluid pressure lines 26 and 27 -may extend to an operators pulpit and be .there controlled by the operator as he observes the advance of a pierced blank. When it is desired to produce blanks of clifaferent sizes, pairs of blocks 10 and 11 having different sized mandrel-supporting and billet-guiding groovesv ma be readily placed upon their supporting ta les 15 and 17. However, it is unnecessary to provide different blocks for each size of blank produced and for each diameter of mandrel bar used, because it is unnecessary to have neat engagements of the blanks-and bars by the blocks.

In Figs. 7 to 10, inclusive, there is shown a modified form of a combined mandrel bar support and billet guide unit comprising a pair of blocks 40 and 41 slidably mounted upon a frame 42 for movements transversely of the line of a piercing pass. 'The ends of these blocks are provided with oppositely dis posed racks 43 and 44, respectively, which mesh with a pinion 45 arranged between them and attached to a shaft 46 which may be rotated by pressure fluid mechanism similar to that shown in Figs. 3 and 4, or by any other suitable means. The tops ofblocks 40 and 41 are provided with upwardly extending arms 47 and 48, respectively, having. grooves in their vertical faces which, when the blocks are in their relative positions shown in Figs.

7 and 9, form a support for a mandrel bar. The tops of the blocks are also provided with upwardly extending arms 50 and 51 which,

vertical deflections, the blocks then being in the position shown in Figs? and 9. When the forward end of the pierced portion of a tube or billet reaches the first pair of these blocks, pinion 45 is rotated to simultaneously move the blocks to the position shown in Figs.

8 and 10 in which their arms 50 and 51 form a billet guide. By varying the positions of the blocks, their arms 50 and 51 may form guides for different sized pierced tubes or billets.

In botlembodiments of the invention, the

pierced portion of atube 'orbillet afiords adequate protection against harmful deflection of a mandrelbar when a pair of blocks are moved from their bar-supporting to their billet-guiding positions. 1 v

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention, and have illustrated and described what I now consider its best embodiments. However, I desire to have it understood that, within the scope of the appended claim the invention may be practiced" otherwise than as specifically illustrated and described.

I claim as my invention:

In a billet piercing mill, the combination of piercing rolls, a mandrel bar provided at its forward end with a mandrel lying in the pass formed by said rolls, a plurality of pairs of movably mounted combined bar-supporting and open-top billet-guiding blocks arranged at spaced intervals intermediate the ends of said bar and having extended bar and billet engaging surfaces, and independent mechanism for separately moving each of said pairsof blocks from its mandrel-supporting to its billet-guiding position.

In testimony whereof, I si my name.

RALPH C. STIEFEL. 

